scholarly journals Cover Feature: Insights into the Target Interaction of Naturally Occurring Muraymycin Nucleoside Antibiotics (ChemMedChem 8/2018)

ChemMedChem ◽  
2018 ◽  
Vol 13 (8) ◽  
pp. 763-763
Author(s):  
Stefan Koppermann ◽  
Zheng Cui ◽  
Patrick D. Fischer ◽  
Xiachang Wang ◽  
Jannine Ludwig ◽  
...  
Keyword(s):  
Nucleoside Antibiotics ◽  
Target Interaction ◽  
Naturally Occurring

scholarly journals Insights into the Target Interaction of Naturally Occurring Muraymycin Nucleoside Antibiotics

ChemMedChem ◽  
2018 ◽  
Vol 13 (8) ◽  
pp. 779-784 ◽  
Author(s):  
Stefan Koppermann ◽  
Zheng Cui ◽  
Patrick D. Fischer ◽  
Xiachang Wang ◽  
Jannine Ludwig ◽  
...  
Keyword(s):  
Nucleoside Antibiotics ◽  
Target Interaction ◽  
Naturally Occurring

scholarly journals Exploiting the Amazing Diversity of Natural Source-Derived Polysaccharides: Modern Procedures of Isolation, Engineering, and Optimization of Antiviral Activities

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 136
Author(s):  
Bimalendu Ray ◽  
Martin Schütz ◽  
Shuvam Mukherjee ◽  
Subrata Jana ◽  
Sayani Ray ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Antiviral Drug ◽  
Natural Source ◽  
Target Interaction ◽  
Charge Densities ◽  
Linkage Pattern ◽  
Naturally Occurring ◽  
Antiviral Activities ◽  
One Step

Naturally occurring polysaccharide sulfates are highly diverse, owning variations in the backbone structure, linkage pattern and stereochemistry, branching diversity, sulfate content and positions of sulfate group(s). These structural characteristics bring about diverse sulfated polymers with dissimilar negative charge densities and structure–activity relationships. Herein, we start with a short discussion of techniques needed for extraction, purification, chemical sulfation, and structural characterization of polysaccharides. Processes of isolation and sulfation of plant-derived polysaccharides are challenging and usually involve two steps. In this context, we describe an integrated extraction-sulfation procedure that produces polysaccharide sulfates from natural products in one step, thereby generating additional pharmacological activities. Finally, we provide examples of the spectrum of natural source-derived polysaccharides possessing specific features of bioactivity, in particular focusing on current aspects of antiviral drug development and drug–target interaction. Thus, the review presents a detailed view on chemically engineered polysaccharides, especially sulfated derivatives, and underlines their promising biomedical perspectives.

Biosynthesis of the Naturally Occurring Nucleoside Antibiotics from Adenosine

1989 ◽  
Vol 8 (5) ◽  
pp. 983-986 ◽  
Author(s):  
Robert Suhadolnik ◽  
Jeffery Hanvey ◽  
Somchai Pornbanlualap ◽  
Joseph Wu ◽  
Kamal Tiwari ◽  
...  
Keyword(s):  
Nucleoside Antibiotics ◽  
Naturally Occurring

Thieme Chemistry Journals Awardees – Where Are They Now? ­Ribosylation of an Acid-Labile Glycosyl Acceptor as a Potential Key Step for the Synthesis of Nucleoside Antibiotics

Synlett ◽  
2017 ◽  
Vol 29 (04) ◽  
pp. 440-446 ◽  
Author(s):  
Christian Ducho ◽  
Daniel Wiegmann ◽  
Anatol Spork ◽  
Giuliana Niro
Keyword(s):  
Total Synthesis ◽  
Antibacterial Agents ◽  
Protecting Group ◽  
Nucleoside Antibiotics ◽  
Naturally Occurring ◽  
Efficient Construction ◽  
Pentenyl Glycosides ◽  
Acid Labile

Naturally occurring nucleoside antibiotics (e.g., muraymycins and caprazamycins) represent attractive lead structures for the development of urgently needed novel antibacterial agents. One major challenge in the total synthesis of muraymycins, caprazamycins, and their analogues is the efficient construction of the densely functionalized aminoribosylated uridine-derived core unit. In order to avoid tedious protecting-group manipulations, we have aimed to conduct the aminoribosylation step with an acid-labile glycosyl acceptor. Therefore, different glycosylation approaches have been studied, with pentenyl glycosides giving the best results.

scholarly journals Aminoribosylated Analogues of Muraymycin Nucleoside Antibiotics

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3085 ◽  
Author(s):  
Daniel Wiegmann ◽  
Stefan Koppermann ◽  
Christian Ducho
Keyword(s):  
Structural Motif ◽  
The Novel ◽  
Reference Compound ◽  
Inhibitory Potency ◽  
Nucleoside Antibiotics ◽  
Peptidoglycan Biosynthesis ◽  
Sar Studies ◽  
Naturally Occurring ◽  
Key Enzyme

Nucleoside antibiotics are uridine-derived natural products that inhibit the bacterial membrane protein MraY. MraY is a key enzyme in the membrane-associated intracellular stages of peptidoglycan biosynthesis and therefore considered to be a promising, yet unexploited target for novel antibacterial agents. Muraymycins are one subclass of such naturally occurring MraY inhibitors. As part of structure-activity relationship (SAR) studies on muraymycins and their analogues, we now report on novel derivatives with different attachment of one characteristic structural motif, i.e., the aminoribose moiety normally linked to the muraymycin glycyluridine core unit. Based on considerations derived from an X-ray co-crystal structure, we designed and synthesised muraymycin analogues having the aminoribose attached (via a linker) to either the glycyluridine amino group or to the uracil nucleobase. Reference compounds bearing the non-aminoribosylated linker units were also prepared. It was found that the novel aminoribosylated analogues were inactive as MraY inhibitors in vitro, but that the glycyluridine-modified reference compound retained most of the inhibitory potency relative to the unmodified parent muraymycin analogue. These results point to 6′-N-alkylated muraymycin analogues as a potential novel variation of the muraymycin scaffold for future SAR optimisation.

scholarly journals Analogues of Muraymycin Nucleoside Antibiotics with Epimeric Uridine-Derived Core Structures

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2868 ◽  
Author(s):  
Anatol Spork ◽  
Stefan Koppermann ◽  
Stephanie Schier (née Wohnig) ◽  
Ruth Linder ◽  
Christian Ducho
Keyword(s):  
Antitumor Agents ◽  
Widespread Application ◽  
Core Motif ◽  
Nucleoside Antibiotics ◽  
Drug Candidates ◽  
Peptidoglycan Biosynthesis ◽  
Sar Studies ◽  
Naturally Occurring ◽  
Promising Target ◽  
Order Of Magnitude

Nucleoside analogues have found widespread application as antiviral and antitumor agents, but not yet as antibacterials. Naturally occurring uridine-derived ‘nucleoside antibiotics’ target the bacterial membrane protein MraY, an enzyme involved in peptidoglycan biosynthesis and a promising target for the development of novel antibacterial agents. Muraymycins represent a nucleoside-peptide subgroup of such MraY-inhibiting natural products. As part of detailed structure-activity relationship (SAR) studies on muraymycins and their analogues, we now report novel insights into the effects of stereochemical variations in the nucleoside core structure. Using a simplified version of the muraymycin scaffold, it was shown that some formal inversions of stereochemistry led to about one order of magnitude loss in inhibitory potency towards the target enzyme MraY. In contrast, epimers of the core motif with retained inhibitory activity were also identified. These 5′,6′-anti-configured analogues might serve as novel chemically tractable variations of the muraymycin scaffold for the future development of uridine-derived drug candidates.

Pathology of Bone Cells in Pigs with Experimental Turbinate Osteoporosis (Atrophic Rhinitis)

1971 ◽  
Vol 29 ◽  
pp. 304-305
Author(s):  
A. W. Fetter ◽  
C. C. Capen
Keyword(s):  
Mucous Membrane ◽  
Bone Cells ◽  
Atrophic Rhinitis ◽  
Infectious Agents ◽  
Metabolic Disturbances ◽  
Progressive Reduction ◽  
Naturally Occurring ◽  
Fundamental Cause ◽  
Osteocytic Osteolysis ◽  
Uncertain Etiology

Atrophic rhinitis in swine is a disease of uncertain etiology in which infectious agents, hereditary predisposition, and metabolic disturbances have been reported to be of primary etiologic importance. It shares many similarities, both clinically and pathologically, with ozena in man. The disease is characterized by deformity and reduction in volume of the nasal turbinates. The fundamental cause for the localized lesion of bone in the nasal turbinates has not been established. Reduced osteogenesis, increased resorption related to inflammation of the nasal mucous membrane, and excessive resorption due to osteocytic osteolysis stimulated by hyperparathyroidism have been suggested as possible pathogenetic mechanisms.The objectives of this investigation were to evaluate ultrastructurally bone cells in the nasal turbinates of pigs with experimentally induced atrophic rhinitis, and to compare these findings to those in control pigs of the same age and pigs with the naturally occurring disease, in order to define the fundamental lesion responsible for the progressive reduction in volume of the osseous core.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

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